Mailing List Archive

[PATCH 04/06]


Introduces the kobjects associated to each tunable min and max value


Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>


---
include/linux/akt.h | 14 ++++
kernel/autotune/akt.c | 148 ++++++++++++++++++++++++++++++++++++++++++++
kernel/autotune/akt_sysfs.c | 16 ++++
3 files changed, 177 insertions(+), 1 deletion(-)

Index: linux-2.6.20-rc4/include/linux/akt.h
===================================================================
--- linux-2.6.20-rc4.orig/include/linux/akt.h 2007-01-29 15:32:48.000000000 +0100
+++ linux-2.6.20-rc4/include/linux/akt.h 2007-01-29 15:47:40.000000000 +0100
@@ -60,9 +60,15 @@ struct tunable_kobject {
/*
* Structure used to describe the min / max values for a tunable inside the
* auto_tune structure.
+ * The abs_value field is used to check that we are not:
+ * . falling under the very 1st min value when updating the min value
+ * through sysfs
+ * . going over the very 1st max value when updating the max value
+ * through sysfs
*/
struct tunable_limit {
ulong value;
+ ulong abs_value;
};


@@ -153,9 +159,11 @@ static inline int is_tunable_registered(
.threshold = (_thresh), \
.min = { \
.value = (_min), \
+ .abs_value = (_min), \
}, \
.max = { \
.value = (_max), \
+ .abs_value = (_max), \
}, \
.tun_kobj = { .tun = NULL, }, \
.tunable = (_tun), \
@@ -169,7 +177,9 @@ static inline int is_tunable_registered(
#define set_tunable_min_max(s, _min, _max) \
do { \
(s).min.value = _min; \
+ (s).min.abs_value = _min; \
(s).max.value = _max; \
+ (s).max.abs_value = _max; \
} while (0)


@@ -217,6 +227,10 @@ extern int unregister_tunable(struct aut
extern int tunable_sysfs_setup(struct auto_tune *);
extern ssize_t show_tuning_mode(struct auto_tune *, char *);
extern ssize_t store_tuning_mode(struct auto_tune *, const char *, size_t);
+extern ssize_t show_tunable_min(struct auto_tune *, char *);
+extern ssize_t store_tunable_min(struct auto_tune *, const char *, size_t);
+extern ssize_t show_tunable_max(struct auto_tune *, char *);
+extern ssize_t store_tunable_max(struct auto_tune *, const char *, size_t);


#else /* CONFIG_AKT */
Index: linux-2.6.20-rc4/kernel/autotune/akt.c
===================================================================
--- linux-2.6.20-rc4.orig/kernel/autotune/akt.c 2007-01-29 15:42:55.000000000 +0100
+++ linux-2.6.20-rc4/kernel/autotune/akt.c 2007-01-29 15:50:31.000000000 +0100
@@ -28,6 +28,10 @@
* unregister_tunable (exported)
* show_tuning_mode (exported)
* store_tuning_mode (exported)
+ * show_tunable_min (exported)
+ * store_tunable_min (exported)
+ * show_tunable_max (exported)
+ * store_tunable_max (exported)
*/

#include <linux/init.h>
@@ -206,3 +210,147 @@ ssize_t store_tuning_mode(struct auto_tu

return strnlen(buffer, PAGE_SIZE);
}
+
+
+/**
+ * show_tunable_min - Outputs the minimum value of a given tunable
+ * @tun_addr: registered tunable structure to check
+ * @buf: output buffer
+ *
+ * This is the get operation called by tunable_attr_show (i.e. when the file
+ * /sys/tunables/<tunable>/min is displayed).
+ * Outputs the current tunable minimum value
+ *
+ * Returns: >0 - output string length (including the '\0')
+ * <0 - failure
+ */
+ssize_t show_tunable_min(struct auto_tune *tun_addr, char *buf)
+{
+ ssize_t rc;
+
+ if (tun_addr == NULL) {
+ printk(KERN_ERR "AKT: tunable address is invalid\n");
+ return -EINVAL;
+ }
+
+ spin_lock(&tun_addr->tunable_lck);
+
+ rc = snprintf(buf, PAGE_SIZE, "%lu\n", tun_addr->min.value);
+
+ spin_unlock(&tun_addr->tunable_lck);
+
+ return rc;
+}
+
+
+/**
+ * store_tunable_min - Sets the minimum value of a given tunable
+ * @tun_addr: registered tunable structure to set
+ * @buf: input buffer
+ * @count: input buffer length (including the '\0')
+ *
+ * This is the set operation called by tunable_attr_store (i.e. when a string
+ * is stored into /sys/tunables/<tunable>/min).
+ *
+ * Returns: >0 - number of characters used from the input buffer
+ * <0 - failure
+ */
+ssize_t store_tunable_min(struct auto_tune *tun_addr, const char *buf,
+ size_t count)
+{
+ ssize_t rc;
+ ulong new_value;
+
+ if (sscanf(buf, "%lu", &new_value) != 1)
+ return -EINVAL;
+
+ if (tun_addr == NULL) {
+ printk(KERN_ERR "AKT: tunable address is invalid\n");
+ return -EINVAL;
+ }
+
+ spin_lock(&tun_addr->tunable_lck);
+
+ if (new_value >= tun_addr->min.abs_value &&
+ new_value < tun_addr->max.value) {
+ tun_addr->min.value = new_value;
+ rc = strnlen(buf, PAGE_SIZE);
+ } else
+ rc = -EINVAL;
+
+ spin_unlock(&tun_addr->tunable_lck);
+
+ return rc;
+}
+
+
+/**
+ * show_tunable_max - Outputs the maximum value of a given tunable
+ * @tun_addr: registered tunable structure to check
+ * @buf: output buffer
+ *
+ * This is the get operation called by tunable_attr_show (i.e. when the file
+ * /sys/tunables/<tunable>/max is displayed).
+ * Outputs the current tunable maximum value
+ *
+ * Returns: >0 - output string length (including the '\0')
+ * <0 - failure
+ */
+ssize_t show_tunable_max(struct auto_tune *tun_addr, char *buf)
+{
+ ssize_t rc;
+
+ if (tun_addr == NULL) {
+ printk(KERN_ERR "AKT: tunable address is invalid\n");
+ return -EINVAL;
+ }
+
+ spin_lock(&tun_addr->tunable_lck);
+
+ rc = snprintf(buf, PAGE_SIZE, "%lu\n", tun_addr->max.value);
+
+ spin_unlock(&tun_addr->tunable_lck);
+
+ return rc;
+}
+
+
+/**
+ * store_tunable_max - Sets the maximum value of a given tunable
+ * @tun_addr: registered tunable structure to set
+ * @buf: input buffer
+ * @count: input buffer length (including the '\0')
+ *
+ * This is the set operation called by tunable_attr_store (i.e. when a string
+ * is stored into /sys/tunables/<tunable>/max).
+ *
+ * Returns: >0 - number of characters used from the input buffer
+ * <0 - failure
+ */
+ssize_t store_tunable_max(struct auto_tune *tun_addr, const char *buf,
+ size_t count)
+{
+ ssize_t rc;
+ ulong new_value;
+
+ if (sscanf(buf, "%lu", &new_value) != 1)
+ return -EINVAL;
+
+ if (tun_addr == NULL) {
+ printk(KERN_ERR "AKT: tunable address is invalid\n");
+ return -EINVAL;
+ }
+
+ spin_lock(&tun_addr->tunable_lck);
+
+ if (new_value <= tun_addr->max.abs_value &&
+ new_value > tun_addr->min.value) {
+ tun_addr->max.value = new_value;
+ rc = strnlen(buf, PAGE_SIZE);
+ } else
+ rc = -EINVAL;
+
+ spin_unlock(&tun_addr->tunable_lck);
+
+ return rc;
+}
Index: linux-2.6.20-rc4/kernel/autotune/akt_sysfs.c
===================================================================
--- linux-2.6.20-rc4.orig/kernel/autotune/akt_sysfs.c 2007-01-29 15:39:05.000000000 +0100
+++ linux-2.6.20-rc4/kernel/autotune/akt_sysfs.c 2007-01-29 15:52:09.000000000 +0100
@@ -54,8 +54,16 @@ struct tunable_attribute tun_attr_##_nam
static TUNABLE_ATTR(autotune, S_IWUSR | S_IRUGO, show_tuning_mode,
store_tuning_mode);

+static TUNABLE_ATTR(min, S_IWUSR | S_IRUGO, show_tunable_min,
+ store_tunable_min);
+
+static TUNABLE_ATTR(max, S_IWUSR | S_IRUGO, show_tunable_max,
+ store_tunable_max);
+
static struct tunable_attribute *tunable_sysfs_attrs[] = {
&tun_attr_autotune, /* to (de)activate auto tuning */
+ &tun_attr_min, /* to play with the tunable min value */
+ &tun_attr_max, /* to play with the tunable max value */
NULL,
};

@@ -75,6 +83,8 @@ static int add_tunable_attrs(struct auto
* @kobj: tunable associated kobject
* @attr: tunable attribute to read. Can be one of:
* tun_attr_autotune
+ * tun_attr_min
+ * tun_attr_max
* @buf: output buffer
*
* Forwards any read call to the show method of the owning attribute
@@ -102,6 +112,8 @@ static ssize_t tunable_attr_show(struct
* @kobj: tunable associated kobject
* @attr: tunable attribute to update. Can be one of:
* tun_attr_autotune
+ * tun_attr_min
+ * tun_attr_max
* @buf: input buffer
* @count: input buffer length (including the '\0')
*
@@ -145,8 +157,10 @@ decl_subsys(tunables, &tunables_ktype, N
* @tunable: tunable structure to be registered
*
* Called by register_tunable()
- * The tunable is a kobject with 1 attributes:
+ * The tunable is a kobject with 3 attributes:
* autotune (rw): enables to (de)activate the auto tuning for the tunable
+ * min (rw): enables to play with the min tunable value
+ * max (rw): enables to play with the max tunable value
*
* Returns: 0 - successful
* <0 - failure

--
-
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